Are you wondering how to solve repetitive tasks with software automation, but you struggle every time you see the word “developer” or “code?” Do you know what APIs are and how they make these tasks easy to solve? In this session, we’ll explore the framework that can apply to mundane tasks (i.e. PowerShell, Pester), and we’ll discuss what open source tools are available to help solve these problems. Walk away with the advice you need to get started!

1. @nutanix #nextconf @RubrikInc
Automation for Anyone
Chris Wahl, Chief Technologist

2. Tweets
Writer
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@ChrisWahl
@ WahlNetwork.com
@ DatanautsPodcast.com
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Networking for VMware Admins
MVP (PowerShell)
VCDX #104 (DCV & NV)
Chris Wahl

3. @nutanix #nextconf @RubrikInc
The Problem with Infrastructure as Code

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Drivers for Change

9. Imperative Declarative

10. The Main Drivers
• You want to test your scripts for bugs
- But you feel bad making other humans do this for you
• You freely admit and acknowledge that testing isn’t possible with your own meat
spatulas
• You also like to automate stuff to avoid more work

11. How Pester Helps
• You write one or more unit tests
• Pester executes them
• The tests either pass or fail
• Results are displayed
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Example 1
Given an input of $false
You expect a return of $false
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14. What Happened?
• The function was evaluated
• The return value was $true
• Pester uses the “Should Be” to compare against $false
• These values don’t match
• The test fails
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15. @nutanix #nextconf @RubrikInc
Let’s Dig Deeper into Pester

16. The Describe Block
• This is your logical grouping of tests
• It’s also a testing scope
- You can define “mock” commands within this scope
• Child objects:
- Context = a group of “it” tests
- It = a single test

17. The Context Block
• A way to logically divide your Describe blocks
- Ex: Run tests under one context / account, then repeat using a different one
- Ex: Test using a “user” account and then again using a “super user” or “admin” account
- Ex: Start with a relative path and then a strict path
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18. The It Block
• This is where you run a specific test
• One set of inputs, one set of outputs
- Don’t get all fancy pants!
• Use the Arrange-Act-Assert format
- Get data
- Test it
- Make sure it ran (code coverage)
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19. Describe, Context, and It
• Describe … a group of API specific tests
- Context … a group of tests against an old API version
• It … runs tests against function1
• It … runs tests against function2
• It … runs tests against function3
- Context … a group of tests against a new API version
• It … (repeat tests from before)
• Describe … a group of parameter tests
And so on …
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20. @nutanix #nextconf @RubrikInc
Example 2
Using “Should” in a variety of ways
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Example 3
What if you can’t use the real code?
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24. @nutanix #nextconf @RubrikInc
Introducing Vester

25. https://github.com/WahlNetwork/Vester

26. Why Does Vester Exist?
• Other configuration software focused on the guests and applications
• Not the hypervisor / cluster config
• You don’t know and/or are afraid of Microsoft DSC
• You can’t (or don’t want to) set up a push or pull server
• You are a contractor doing an audit of a customer’s environment
• You’re looking for a very quick way to create your own custom tests
• You aren’t able to install agents or are just generally opposed to agents
for management
• You’re comfortable with PowerShell as a cross-platform development
framework

27. Building a New Configuration

28. Configuration in JSON Format

29. Testing Configuration JSON vs Reality

30. Remediation of Configuration Drift

31. @nutanix #nextconf @RubrikInc
In Conclusion

32. The Future!
• Infrastructure as Code means no boundaries
- The framework supports any configuration requirements
• Fork the project
- Nutanix + Pester = Nester? ☺
- Lots of great use cases available!
• Consistency?
- Deploy like-for-like environments globally
- Make sure you don’t mess things up with your meat spatulas
• STIGs?
- Acropolis Virtual Storage Controller STIG
- Nutanix Prism Web Server STIG (for tomcat)
- Nutanix Prism Proxy Server STIG (for Apache)
- Nutanix JRE8 STIG
- AHV STIG

33. Thoughts
• Keep your functions as small as possible
- I prefer one logical statement per function
• Unit test the functions rather than the workflows
• Embrace TDD and creating tests for everything you do
- Test Driven Development (of infrastructure, too!)
• As you encounter an issue, build a test for it
- That way it never happens again
- Crush tribal knowledge!
• Be kind to your future self
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Future You
Past You

35. Resources
• Pester
- https://github.com/pester/Pester
• The Pester Book
- https://leanpub.com/pesterbook
• PowerShell Summit “Lightning Demos”
- https://github.com/RamblingCookieMonster/CommunityLightningDemos2017
• xUnit Test Patterns: Refactoring Test Code
- http://amzn.to/2pcaKQK
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36. Fill out the survey
found in this session’s
page on your agenda
for a chance to WIN!

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@ChrisWahl | chris.wahl@rubrik.com